Systems and methods for controlling an aircraft using dissimilar air data

Examples of the present disclosure generally relate to systems and methods for controlling an aircraft, and more particularly to systems and methods for controlling an aircraft using dissimilar air data from different air data sensors.

Aircraft are used to transport passengers and cargo between various locations. Known aircraft include air data sensors that detect certain characteristics of air surrounding the aircraft. Air data from the air data sensors can be used to control operation of the aircraft. However, under certain circumstances, the air data may not be reliable. For example, if the air data sensors are struck by a bird as the aircraft is in flight, the air data sensors may provide unreliable air data. As another example, during icing conditions, the air data sensors may also provide unreliable air data. In such circumstances, a pilot of the aircraft may be required to manually operate and land the aircraft at an airport as soon as possible with incorrect and potentially misleading information about the state of the flight of the aircraft, as well as with degraded system operation.

In general, modern aircraft include fairly robust air data systems. Again though, the air data systems can be affected by external threats, such as icing, bird-strikes, volcanic ash, and the like. Such threats can potentially corrupt all air data sensors at the same time. Thus, despite redundancy, an external threat can potentially corrupt all measurements at once, typically called a common-cause event. In some known aircraft, pilots would be presented with multiple sources of airspeed and altitude, and they would have to decide which information to trust if something appeared wrong. In more recent aircraft, software performs comparison monitoring and voting to present a pilot with a trusted measurement. However, if all the measurements are wrong, there is no way to provide accurate information. Such monitoring systems can then flag data as erroneous or unreliable.

Nevertheless, even if such errors can be detected, known systems may only indicate that the data is invalid. Thus, a pilot can be informed of erroneous data, but then typically has to revert to simpler backup control laws, which may sacrifice one or more safety enhancing functions.

A need exists for an improved system and a method for operating an aircraft using air data from air data sensors. Further, a need exists for a system and a method that ensure accurate and reliable air data is received from air data sensors. Also, a need exists for an improved system and method for providing air data to flight crew and aircraft systems.

With those needs in mind, certain examples of the present disclosure provide a system including air data sensors configured to detect one more characteristics of air surrounding an aircraft. At least three of the air data sensors differ in type. In at least one example, at least three of the air data sensors differ in type. The air data sensors are configured to output air data. A flight control unit is in communication with the air data sensors. The flight control unit is configured to receive the air data from the air data sensors and control at least one aspect of the aircraft based on at least a portion of the air data.

In at least one example, the flight control unit is further configured to vote in relation to the air data from the air data sensors. For example, the flight control unit is configured to vote in relation to redundant signals by selecting a mid-value to prevent an errant signal from affecting a voted output.

In at least one example, the flight control unit is configured to vote redundant measurements of each type of air data sensor, and provide multiple voted signals of a given parameter to determine if any of the voted signals are corrupted. In at least one example, the flight control unit is configured to select the types of air data sensors that behave differently in a presence of different threats in response to at least two of the types being corrupted. In at least one example, the flight control unit is configured to determine that a majority of the air data sensors are corrupted when none of the air data matches. In at least one example, the flight control unit is configured to vote by voting two types of the air data sensors, and reserving a third type of the air data sensors as a monitoring signal.

The system can also include a display that shows the air data.

In at least one example, the air data sensors include one or more first flush mounted pressure sensors, one or more multi-function probes (MFPs), one or more pitot probes, one or more angle of attack (AOA) vanes, and one or more second flush mounted pressure sensors. As a further example, the one or more first flush mounted pressure sensors include a pair of first flush mounted pressure sensors that can be symmetrical with respect to a central longitudinal plane of the aircraft. As a further example, the one or more MFPs include a pair of MFPs that can be about symmetrical with respect to the central longitudinal plane of the aircraft. As a further example, the one or more pitot probes include a pair of pitot probes that can be about symmetrical with respect to the central longitudinal plane of the aircraft. As a further example, the one or more AOA vanes include a pair of AOA vanes that can be about symmetrical with respect to the central longitudinal plane of the aircraft. As a further example, the one or more second flush mounted pressure sensors include one or more pairs of second flush mounted pressure sensors that can be about symmetrical with respect to the central longitudinal plane of the aircraft. In at least one other example, the pairs of air data sensors may not be symmetrical with respect to the central longitudinal plane of the aircraft.

The air data sensors can also include one or more total air temperature (TAT) probes.

In at least one example, the one or more first flush mounted pressure sensors, the one or more MFPs, the one or more AOA vanes, and the one or more second flush mounted pressure sensors are not coupled to pneumatic connections.

Certain examples of the present disclosure provide a method including detecting, by air data sensors, one more characteristics of air surrounding an aircraft, wherein at least three of the air data sensors differ in type, and wherein the air data sensors are configured to output air data; receiving, by a flight control unit in communication with the air data sensors, the air data from the air data sensors; and controlling, by the flight control unit, at least one aspect of the aircraft based on at least a portion of the air data.

The method can also include voting, by the flight control unit, in relation to the air data from the air data sensors. The method can also include showing the air data on a display.

Certain examples of the present disclosure provide an aircraft including air data sensors, and a flight control unit, as described herein.

The foregoing summary, as well as the following detailed description of certain examples will be better understood when read in conjunction with the appended drawings. As used herein, an element or step recited in the singular and preceded by the word “a” or “an” should be understood as not necessarily excluding the plural of the elements or steps. Further, references to “one example” are not intended to be interpreted as excluding the existence of additional examples that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, examples “comprising” or “having” an element or a plurality of elements having a particular condition can include additional elements not having that condition.

illustrates a simplified block diagram of an aircraft, according to an example of the present disclosure. The aircraftincludes a systemincluding air data sensorsin communication with a flight control unit, and a displaythrough one or more wired or wireless connections. In at least one example, the air data sensorsinclude one or more multi-function probes, one or more flush mounted pressure sensors, one or more angle of attack vanes, one or more total air temperature probes, and/or the like. The air data sensorsoutput air data, which is received by the flight control unitand the display.

In at least one example, at least two of the air data sensorsdiffer in type from one another (for example, multi-function probes differ in type from flush mounted pressure sensors, angle of attack vanes, and total air temperature probes). As such, the air data sensorscan be dissimilar, and output dissimilar air data. Because the air data sensorsare of different types, the air data sensorsbehave and react differently to external threats, such as bird strikes, icing, and the like. The different air data sensorssense air parameters in different ways, thereby providing dissimilar responses. The dissimilar response characteristics allow for sensor isolation and detection, and also increase the chances of at least one sensor type surviving a common threat exposure.

In at least one example, at least three of the air data sensorsdiffer in type from one another. With three different types of air data sensors, the flight control unitcan readily discern if air data from one type of air data sensor(s)does not agree with air data from the other two types of air data sensor(s). In at least one example, another source of air data can be an estimate derived from other sensor inputs. Alternatively, the other source can be a different air data measurement.

In at least one example, the flush mounted pressure sensors (such as first flush mounted pressure sensors and second flush mounted pressure sensors) can cooperate to provide a network of sensors that calculate different parameters (such as total pressure, angle of attack, angle of sideslip, and/or static pressure). As such, the various flush mounted pressure sensors can work together as a network or array of sensors. The number of such sensors can vary.

The flight control unitis configured to operate various aspects of the aircraft. The flight control unitcan include a plurality of control units, processors, or the like that are configured to operate the various aspects of the aircraft. In at least one example, the flight control unitis configured to control flight of the aircraft. For example, the flight control unitcan be configured to operate engines, flight control surfaces, and/or the like to control the aircrafton the ground and in flight. The flight control unitis configured to provide auto-pilot operation. As a further example, the flight control unitis configured to assist a pilot in operating the aircraft. The flight control unitreceives the air datafrom the air data sensorsand operates the aircraftbased on the air data.

The displayis an electronic monitor, such as a computer monitor, an electronic display panel, or the like, such as within a flight deck or cockpit of the aircraft. The displayreceives the air datafrom the air data sensors, typically via the flight control unit, and shows information regarding the air dataon the display. In this manner, a pilot can view the information regarding the air data on the display.

As described herein, the systemincludes the air data sensorsconfigured to detect one more characteristics of air surrounding the aircraft. At least two of the air data sensorsdiffer in type. In other example, at least three of the air data sensorsdiffer in type. The air data sensorsare configured to output the air data. Air datafrom different types of sensors is dissimilar. The flight control unitis in communication with the air data sensors. The flight control unitis configured to receive the air datafrom the air data sensorsand control at least one aspect of the aircraftbased on at least a portion of the air data. In at least one example, the flight control unitis further configured to vote regarding the air datafrom the air data sensors.

illustrates a simplified schematic top view of an aircraft, according to an example of the present disclosure. The aircraftincludes numerous air data sensors. For example, the air data sensors include a pair of flush mounted pressure sensorsand, which can be configured to measure angle of sideslip. The flush mounted pressure sensorsandcan be proximate to a noseof the aircraft. The flush mounted pressure sensorsandcan be symmetrical with respect to a central longitudinal planeof the aircraft. For example, the flush mounted pressure sensorcan be a right flush mounted pressure sensor positioned a first distance from the central longitudinal plane, and the flush mounted pressure sensorcan be a left flush mounted pressure sensor positioned a second distance from the central longitudinal plane, in which the second distance is the same or similar length (such as within +/−5%), but opposite from the first distance. Optionally, the distances may differ. The flush mounted pressure sensorsandare in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The flush mounted pressure sensorsandmay not be coupled to pneumatic connections, thereby reducing overall weight of the aircraftand improving fuel efficiency. Optionally, the flush mounted pressure sensorsandmay be coupled to external pneumatic connections.

The first pair of flush mounted pressure sensorsandprovide dissimilar air data. That is, the flush mounted pressure sensorprovides air data that differs from that of the flush mounted pressure sensor. The air data from the flush mounted pressure sensorsandcan be similar in that each includes the same or similar sensing mechanisms.

In at least one example, the air data sensors also include at least one multi-function probe (MFP). For example, the air data sensors can include a pair of MFPsandthat are aft from the first pair of flush mounted pressure sensorsand. The flush mounted pressure sensorsandcan be closer to the noseof the aircraftthan the MFPsand. Optionally, the first pair of flush mounted pressure sensorsandmay not be closer to the noseof the aircraftthan the MFPsand. The MFPsandcan be symmetrical with respect to the central longitudinal planeof the aircraft. For example, the MFPcan be a right MFP positioned a third distance from the central longitudinal plane, and the MFPcan be a left MFP positioned a fourth distance from the central longitudinal plane, in which the fourth distance is the same or similar length (such as within +/−5%), but opposite from the third distance. The MFPsandare in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The MFPsandmay not be coupled to pneumatic connections, thereby reducing overall weight of the aircraftand improving fuel efficiency. The pair of MFPsandprovide dissimilar air data from one another, as well as the first pair of flush mounted pressure sensorsand. The air data from the MFPsandcan be similar in that each includes the same or similar sensing mechanisms. The MFPprovides air data that differs from that of the MFP. The MFPsandcan be configured to operative independently and automatically, and can further be configured to operate through enhanced calibration techniques.

In at least one example, the MFPs provide air data including pitot and static pressure, air speed, angle of attack and angle of sideslip. Each MFP can include an air data computer and can be devoid of pneumatic tubing. In at least one example, the MFPs include a receiving tube having multiple openings configured to receive air. The numerous openings are configured to provide information regarding total air pressure, and pressure-based angle of attack information, as well as static air pressure.

In at least one example, the air data sensors also include a pair pitot probesandthat can be aft from the MFPsandThe MFPsandcan be closer to the noseof the aircraftthan the pitot probesand. The pitot probesandcan be symmetrical (or about symmetrical, such as deviating less than 5% from symmetry) with respect to the central longitudinal planeof the aircraft. For example, the pitot probecan be a right pitot probe, and the pitot probecan be a left pitot probe. The pitot probecan be coupled to a pneumatic conduitthat connects to a first air data module, which is in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. Optionally, the pitot probecan include co-located electronics in which there is not a separate air data module. Similarly, the pitot probeis coupled to a pneumatic conduitthat connects to a second air data module, which is in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The pair of pitot probesandprovide dissimilar air data from one another, as well as the first pair of flush mounted pressure sensorsandand MFPsand. The pitot probeprovides air data that differs from that of the pitot probe. The air data from the pair of pitot probesandcan be similar in that each includes the same or similar sensing mechanisms.

In at least one example, the air data sensors also include a pair of angle of attack (AOA) vanesandthat are aft from the pitot probesand. The pitot probesandcan be closer to the noseof the aircraftthan the AOA vanesand. The AOA vanesandcan be symmetrical (or about symmetrical) with respect to the central longitudinal planeof the aircraft. For example, the AOA vanecan be a right AOA vane, and the AOA vanecan be a left AOA vane. The AOA vanesandare in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The pair of AOA vanesandprovide dissimilar air data from one another, as well as the first pair of flush mounted pressure sensorsand, the MFPsand, and the pitot probesand. The AOA vaneprovides air data that differs from that of the AOA vane. The air data from the pair of AOA vanesandcan be similar in that each includes the same or similar sensing mechanisms.

In at least one example, the air data sensors also include a total air temperature (TAT) probe, which is aft from the AOA vane(or optionally, the AOA vane). An additional TAT probe can also be used. The AOA vanecan be closer to the noseof the aircraftthan the TAT probe. Optionally, the TAT probecan be located closer to the nose. The TAT probeis in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The TAT probeprovides dissimilar air data (for example, different air data) from the first pair of flush mounted pressure sensorsand, the MFPsand, the pitot probesand, and the AOA vanesand. In at least one example, the TAT probeoutputs a TAT signal that is used by the flight control unitto compute true airspeed based on total air pressure, and further based on static pressure detected by other air data sensors.

In at least one example, the air data sensors also include a second pair of flush mounted pressure sensorsandthat are aft from AOA vanesand, and a third pair of flush mounted pressure sensorsandthat are aft from the second pair of flush mounted pressure sensorsand. The first pair of flush mounted pressure sensorsandcan be symmetrical with respect to the central longitudinal planeof the aircraft. Further, the third pair of flush mounted pressure sensorsandcan be symmetrical with respect to the central longitudinal planeof the aircraft. The flush mounted pressure sensors,,, andare in communication with the flight control unit(and optionally the display) through one or more wired or wireless connections. The flush mounted pressure sensors,,, andare not coupled to pneumatic connections, thereby reducing overall weight of the aircraftand improving fuel efficiency. In at least one other example, the flush mounted pressure sensors,,, andcan be coupled to pneumatic connections. The flush mounted pressure sensors,,, andprovide dissimilar air data from one another, as well as the first pair of flush mounted pressure sensorsand, the MFPsand, the pitot probesand, and the TAT probe

Optionally, the aircraftcan include more or less sensors than shown. Further, the air data sensors can be located at different areas than shown.

In operation, the flight control unitreceives air data from all of the air data sensors-. The flight control unitcontrols operation of the aircraft based on the air data received from the air data sensors-. Information regarding the air data can be shown on the display, for example. Because the air data is from numerous sensors, the air data from each of the air data sensors is dissimilar. The dissimilar air data received from all of the air data sensors-is analyzed by the flight control unit to determine reliability and accuracy. The numerous air data sensors-provide redundancy to ensure that accurate air data is received by the flight control unitfrom at least one of the air data sensors.

The flight control unitreceives the dissimilar air data from the numerous air data sensors-and retains valid air data even in the presence of common-cause threat scenarios. In at least one example, the flight control unitis configured to select one or more of the sensors-in relation to valid air data. Because the aircraftincludes numerous air data sensors of different types (for example, flush mounted pressure sensors, MFPs, pitot probes, a TAT probe, and/or the like), the different types of air data sensors behave differently in the presence of air data external threats (such as bird strikes, icing, or the like), and also have different levels of exposure to corruption by each threat. That is, the dissimilar air data sensors have different weaknesses, so that for a given threat, one air data sensor may be corrupted but one or more others is not corrupted.

The flight control unitreceives the dissimilar air data from the numerous air data sensors-and performs a voting operation in relation to the dissimilar air data. In at least one example, sensors of a single type can be simultaneously corrupted, but such will not affect the accuracy of the voted air data parameters. In this manner, the flight control unitcan also identify which sensors may be corrupted, which also leads to retaining full flight control capability and display integrity.

As an example, the flight control unitreceives air data from each of the MFPsandand can initially perform a correction in relation to such data. The flight control unitcan then perform an MFP triplex signal selection fault detection with respect to the air data received from the MFPsandregarding total air pressure, static air pressure, and angle of attack. The flight control unitreceives air data from all of the air data sensors-and can perform such corrections and triple signal selection fault detections with respect to the received air data. The flight control unitcan perform a voting operation with respect to the dissimilar air data from the different air data sensors-. The voting operation can include determining a middle value, with outlying values being slow rate equalized to the middle value signal. The flight control unitcan operate the aircraft based on the middle value, for example. If outlying values exceed a predetermined threshold, the flight control unitcan discard such outlying value(s). The flight control unitcan also identify the air data sensors from which such outlying value(s) are received. In at least one example, the flight control unitperforms the voting operation by the following: equalization, which seeks to remove any small, steady-state offsets in sensor measurements from corresponding outputs; source error correction, which accounts for the location of the individual sensors and performs a local-to-freestream correction; air data conversion, which takes pressure data and converts it to relevant air data parameters such as airspeed and Mach; and a redundancy management algorithm. In at least one example, rather than using a single triple system for each parameter, the flight control unituses a dual-layered voting and monitoring scheme. The first layer votes and monitors all of the air data sensors-in pairs, based on type. For example, the flight control unitvotes two MFP measurements together in one voter, while two AOA vanes are voted in another voter. These two outputs from the first layer are then voted together with a synthetic estimate of angle of attack in the second layer to produce a trusted measurement of angle of attack. This dual layer voting architecture allows not only for the detection and isolation of erroneous data from a single sensor, but also successfully detects and isolates erroneous data from common sensor types without allowing the trusted output to become corrupted. In at least one example, the flight control unitcan modify a first layer signal selection fault detection voting scheme for angle of attack by providing a first vote with respect to vane angle of attack, a second vote with respect to MFP angle of attack, and a third vote with respect to synthetic inertial angle of attack based on pitch attitude, static pressure, and synthetic pressure.

In at least one example, the flight control unitdetects the signals from the air data sensorsand performs the voting to (1) provide air data measurements that remain accurate and undisturbed when any single air data sensor, or even all air data sensors of a given type are corrupted, and (2) ensure detection and invalidation of a given air data parameter if the majority of sensor types (for example, two out of three dissimilar sources) are corrupted at the same time in a worst-case scenario. If the signals received from the air data sensorsare not voted (for example, one signal was used until it was determined to be corrupted, then the voting switches to a next source), the flight control unitmay then determine that, for a period of time, the first corrupted data can still be used by various systems until the flight control unitdetermines that the data is unusable and switches to other data for analysis. In at least one example, the flight control unitvotes in relation to redundant signals, such as by selecting a mid-value, to prevent one errant signal from affecting a voted output during the time it takes to determine one signal is unusable and flag it as erroneous.

By adding dissimilarity, more layers of measurements are added such that there is redundancy in measurements of a given sensor type, and redundancy in measurements of a given air data parameter coming from different sensor types as well. The flight control unitcan use various different voting schemes.

For example, the flight control unitcan be configured to vote the redundant measurements of each sensor type first, such as by creating a voted MFP angle of attack signal, then another voted vane angle of attack, and optionally a voted angle of attack from a flush mounted pressure sensor array if there are enough flush sensors to produce more than one AOA measurement. In this case, an erroneous signal of any one sensor does not propagate past the first voting layer. Next, since there is now a multiplicity of voted signals of a given parameter (in this example, three voted AOA measurements), those voted signals enter yet another voting layer, which prevents one voted signal from corrupting the overall voted parameter. In this example, if there are two MFP sensors and both were corrupted at the same time, the voted MFP signal may be corrupted. However, when that signal is voted with the other two sources, the signal is voted out of consideration. Because there are still two other sources of data that are still acceptable, the flight control unitdetermines there is an acceptable measurement. If, however, two sensor types are corrupted, the flight control unitcan select the sensor types that behave differently in the presence of various threats, thereby ensuring that the two corrupted signals at the second layer behave differently, and hence all three signals mismatch at the second layer. Further, the flight control unitcan further determine that when nothing matches, a majority of sensors are corrupted and therefore there is no valid data, thereby providing a fail-safe.

In an at least one example, the first voting layer can instead vote on individual sensor outputs from dissimilar sensor types, and there can still be a second voting layer that votes the outputs of the first voting layer.

In at least one example, two sensor types can be voted, and the third sensor type can be reserved simply as a monitoring signal. As a different example, the system can include multiple MFPs, multiple flush mounted pressure sensors, and a synthetic/estimated parameter that uses an algorithm and other non-air data sensors. There can still be a first layer vote and a second layer vote, as described. However, there are only two voted signals from the first layer, and if both of those are corrupted, then the voted signal from the second layer may also be corrupted. If the second layer signal is compared to a third signal in a comparison monitor, and the two fail to match, then the flight control unitcan invalidate the air data signal or parameter. In such a scenario, the third signal is not a tie-breaker in the voting, but can still be used to provide the fail-safe state. In this example, the flight control unitcan vote same-type signals or mixed-type signals in the first layer, so either of the first two variants can be combined with this version.

In at least one other example, the flight control unitcan perform a super vote, in which all parameters are voted at once. In at least one example, the voting schemes do not necessarily need to have a mid-value select vote. Instead, some voting schemes can utilize an average, or can pick one and then switch if that one mis-compares from the others.

Examples of the present disclosure provide systems and methods for operating an aircraft that includes a combined use of multi-function air data probes and other air data sensors to provide dissimilar air data. Further, in at least one example, the systems and methods include the flight control unitthat can utilize voting algorithms to manage air data disagreements during common mode threats, thereby enabling isolation of corrupted sensors even under extreme threat environments, and hence a fail-safe operational flight control system.

illustrates a side view of a front of an aircraft, according to an example of the present disclosure. The aircraftincludes a flight deck or cockpitproximate to the nose. Referring to, the sensors are positioned to avoid physical interference. Further, in at least one example, the AOA vanesandcan be positioned on a half-breadth line, which increases local to free-stream linearity while reducing Mach and sideslip effects. The pitot probesandcan be positioned to provide low error corrections and avoid nose gear wake. The MFPsandcan be positioned to provide comparable static source error correction, total source error correction, and angle of attack corrections with a reduced magnification factor. The first pair of flush mounted pressure sensorsandcan be positioned to provide reduced Mach and angle of attack coupling.

illustrates a schematic block diagram of a control unit, according to an example of the present disclosure. The flight control unitshown incan be configured as shown in. In at least one example, the control unitincludes at least one processorin communication with a memory. The memorystores instructions, received data, and generated data. The control unitshown inis merely exemplary, and non-limiting.

As used herein, the term “control unit,” “central processing unit,” “CPU,” “computer,” or the like may include any processor-based or microprocessor-based system including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASICs), logic circuits, a quantum computer, and any other circuit or processor including hardware, software, or a combination thereof capable of executing the functions described herein. Such are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of such terms. For example, the flight control unitmay be or include one or more processors that are configured to control operation, as described herein.

The flight control unitis configured to execute a set of instructions that are stored in one or more data storage units or elements (such as one or more memories), in order to process data. For example, the flight control unitmay include or be coupled to one or more memories. The data storage units may also store data or other information as desired or needed. The data storage units may be in the form of an information source or a physical memory element within a processing machine.

The set of instructions may include various commands that instruct the flight control unitas a processing machine to perform specific operations such as the methods and processes of the various examples of the subject matter described herein. The set of instructions may be in the form of a software program. The software may be in various forms such as system software or application software. Further, the software may be in the form of a collection of separate programs, a program subset within a larger program, or a portion of a program. The software may also include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or in response to results of previous processing, or in response to a request made by another processing machine.

The diagrams of examples herein may illustrate one or more control or processing units, such as the flight control unit. It is to be understood that the processing or control units may represent circuits, circuitry, or portions thereof that may be implemented as hardware with associated instructions (e.g., software stored on a tangible and non-transitory computer readable storage medium, such as a computer hard drive, ROM, RAM, or the like) that perform the operations described herein. The hardware may include state machine circuitry hardwired to perform the functions described herein. Optionally, the hardware may include electronic circuits that include and/or are connected to one or more logic-based devices, such as microprocessors, processors, controllers, or the like. Optionally, the flight control unitmay represent processing circuitry such as one or more of a field programmable gate array (FPGA), application specific integrated circuit (ASIC), microprocessor(s), and/or the like. The circuits in various examples may be configured to execute one or more algorithms to perform functions described herein. The one or more algorithms may include aspects of examples disclosed herein, whether or not expressly identified in a flowchart or a method.

As used herein, the terms “software” and “firmware” are interchangeable, and include any computer program stored in a data storage unit (for example, one or more memories) for execution by a computer, including RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory. The above data storage unit types are exemplary only, and are thus not limiting as to the types of memory usable for storage of a computer program.